There are already known various constructions of pumped optical waveguide lasers, among them such utilizing fully or partially reflective coatings on the respective end faces delimiting the laser resonance cavities in the optical waveguides, and such using external mirrors to delimit the laser cavities. Even though these solutions have achieved quite a degree of success and/or acceptance in the laser manufacturing and utilization fields, they still suffer of certain drawbacks. An important disadvantage of such lasers that is particularly felt in the optical communication field is that, even when the optical fiber laser is constructed as a so-called single-mode optical fiber laser, it typically lases in a great number of longitudinal modes. This, of course, significantly degrades the properties of the laser radiation issued by the optical fiber laser due to mode beating and other optical effects, thus considerably reducing the utility of the issued laser beam.
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide a pumped optical fiber laser arrangement which does not possess the disadvantages of the known arrangements of this kind.
Still another object of the present invention is so to develop the arrangement of the type here under consideration as to improve its performance in terms of obtained output power, while simultaneously obtaining excellent mode discrimination.
It is yet another object of the present invention to devise arrangements of the above type which are able to achieve high conversion efficiencies with relatively short optical fiber lasers.
A concomitant object of the present invention is to design the optical fiber laser arrangement of the above type in such a manner as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation.